Triple valve.



J. R. SNYDER.

TRIPLE VAEVE.

APPLICATION FILED FB- I3, 1914.

Patent ed Jan. 16,1917.

' gains-Super u.

WITNESSES E TOR mm 00., mm. WWW. L

JACOB Russ sNYnERjor m se ms, PENNSYLVANIA, AssreNoR ro rrrrsisunsn 4AIR BRAKE COMPANY, or rrrrsnunen, PENNSYLVANIA, A oonr'ona'rroNor rnN :sL IA- 1 ball 'whomiz'i may} comm; I

Be'itknowi-i thatI, Jiiooia Rusi-r S rbER,

a resident of Pittsburgh, in the county of.

Allegheny and State of Pennsylvania, have nventeda newand usefulImprovement'm Triple Valves, of which the following 1s a specification.V.

This invention relates to triple valves for air brake systems, and moreparticularly 'for freight car service. I I The principal object ofthefinvention is to provide triple valve mechanisnrwhereby after fullservice application of the brakes,

such as produced by equilization between the auxiliary reservoir, trainpipe'and the usual brake cyllnder aC ldltlQIlfll' braking power can besecured so as to hold, the car when' loaded on steep grades withouttheuse To this end the triple of hand brak es. valve mechanism is soarranged that after full service application, by further reductionoftrain. pipe pressure, fluid pressure can graduated into. a supplementaryor high pressure brake cylinder at the will of the engineerand to anydesired degree pracpower can be increased so as to'hold the car on steepgrades when loaded.

Further objects of the nventionlare to provide a triple valve having allof the usual functions of triple valves and in addition being soarranged as to produce a quick release of the brakes throughout thetrain, provide for a quick serial, action of the brakes throughout thetrain n servlce application as well as in emergency ap.-.

plication, and, further, to supply'the service brake cylinderwithpressure in proportion to train pipe reduction and irrespective ofvariations in piston travel, and to maintain said brake cylinderpressure against leakage in service as Well as in high pressureapplications and which; valve "performs these various functions by muchsimpler and jrmrLE' VALVEQ Specification of Letters Patent.

- PateritedJamlG,1917.

Application area February 13 1914. Serial Nb. 818,567.

less complicated construction than prior valves capablejpjf effectingonly a part of these results and "functions The invention comprises theconstruction and arrangement of a triple valve herein-v atter describedand claimed.

In the accompanying drawings Figure 1 is a vertical longitudinal sectionthrough triple valvelembodying the invention and showing the "same infull releaseand runningposition, and being taken onthe line11,-Fig.-2.,Fig. Zis'a yertical transverse section on the line; 2. 2,Fig. 1; Fig. 3' is a horizontal section on theline 3.3, Figs;

1 and 5, with the piston stem and slide valves removed, and showing theconnec-[ tions to the supplemental and, auxiliary.

service antlhighpressure brake cylinders;

direction of the arrows; Fig. 431s a cross reservoirs the pressurechamber and the section on the line n+4, Fig.3, looking in the directionof the arrows;'Fig. 5 is an end ,view of the valve casing, parts of thevalve being-omitted; Figs. 6,7, 8, 9, 10,11 and 1-2 are diagrammaticviews showing the main valve seat and inain slide valve in plan view andthe graduating valve 7 in horizontal section and showing difierent-positons ot the valve;;Fig. .6showing the same in full and quick releaseposition, 7 in jquickservice position,Fig. 8 in full service position, 7

Fig. 9 in service lap position, Fig. 10 in high pressure applicationposition Fig." 11 in high. pressure lapposition, and Fig. 1:2 inemergency application position; Fig. 13 is a plan view of the main slidevalve; Fig. 14L isa similar view of the graduating slide valve; Figs.15,16 and 17 are diagrammatic views of the supplementary valve seat inplan and the supplementary slidevalve in.

horizontal section and showing the different positions of this valve'Fig.' loshowing the same in release position; Fig. .16 inlap. andrunning position; Fig. 17 in application position, and Fig. 18 in adetail perspective view of the mainvalve bushing.

The triple valve: inits general form, con- -struction and arrangement.follows-i the standard type of Westinghouse and similar Valves. Itcomprises a main body or casing 1 provided at one end with a fiat face 2for valves; nected by pipe 9 with the end of chamber or a open when themain the usual connection to the auxiliary reservoir and brakecylinders, when desired, and is closed atits opposite end by the head orcap 3. In this casing is the usual chamber 4 in which works the mainpiston 5 which is provided with a stem 6 extending into the chamber orbore 7 and actuating the slide The auxiliary reservoir ,8 is conbore 7and is normally charged through the feed groove 10 in the bushingforming the wall of chamber 4, which feed groove is piston is in fullrelease position.

The train pipe is connected to the passage 11 which extendslongitudinally through the bottomportion'of the casing on one side ofits center line and communicates with the chamber 12 in the head or cap3, from which chamber communication is had with piston chamber 4 throughport 13.

The lower part of the bushing 14 in chamber orbore 7 provides a seat 15for the main slide valve 16 which, together with the supplementary orgraduating valve 17, which rests upon the top of the main slide valve16, is actuated by the piston stem 6. The valve seat 15 is provided withthe ports and passages shown in Fig. 3, to-wit:-two exhaust ports,marked 18 and 19 respectively and which communicate with a cored outpassage 20 communicating with the atmosphere through the passage 21; aport 22 near one end of the valve'seat and which. communicates through apassage 23' with the train pipe passage 11; a port 2 4 locatedsubstantially transversely of port 22 and communicating through passage25 with a longitudinal passage 26 from which a pipe 27 leads to theservice brake cylinder 28; an

' oblong transverse Port 29 located near the opposite end of the valveseat and communicating through passage 30 and pipe 31 with the highpressure brake cylinder 32; an L-shaped port 33 located longitudinallyadjacent to the high pressure brake cylinder port 29 and transverselyadjacent to the exhaust port 19 and communicating through passage 34 andpipe 35 with the supplementary reservoir 36; a circular port 37 locatedadjacent one end of the valve seat and communicating through passage 38with the pressure chamber of the supplemental valve hereinafterdescribed; and a port 39 connected by passage40 with the oppositeside ofthe pressure chamber piston as hereinafter described; The valve seat isalso provided with a groove or slot 41 extending inwardly from one sideedge and serving in full release position of the valve to form a portionof a connection from the-chamber 7 to the supplementaryvreservoir forcharging the latter, as will hereinafter more fully appear.

' The mainslide valve 16 has a slight lost motion between collars 42 and43 011 the main piston stem 6, and is provided with the ports andcavities shown in Fig. l3,'towit,

an L-shaped cavity 45 adjacent to one end;

port 47 which on the lower face of the valve is enlarged tosubstantially square-shape;

three circular ports 48, 49 and 50 substantially in line with each otherlongitudinally of the valve, and a smaller circular port 51 transverselyin linewith port 49. One edge of this valve is also cut away as at 52,and both inner corners are cut away, one corner being cutaway foraconsiderable distance longitudinally of the valve, as at 53, and theother corner being cut away transversely of the valve, as at 54. Theouter end of the valve is provided with a projection 55.

The upper face of'the main slide valve forms the seat for the graduatingvalve 17 which is held without lost motion between collars 56 and 56 onthe main piston stem 6.

provided a casing 60 for a supplementary valve mechanism, in this casingis a chamber 61 in which'works a piston 62 provided with a stem 63projecting into the pressure chamber 64 and carrying an arm orprojection 65 which actuates the supplementary slide valve 66 working onthe valve seat 67. The piston stem 63 extends through apartition or wall70 and beyond said partition or wall carries a smaller piston 71 workingin a chamber 72'. A stuffing-box 73 surrounds the piston stem 63' andprevents air from leaking from pressure chamber 64 to the chamber 72.The piston stein extends beyond the piston 71, and has a reduced portion74 which is loosely surrounded by two collars marked 75 and 76respectively, between which is a compression spring 77. The collar 75 isadapted to seat against a shoulder 78 and the collar 76 is adapted toseat against a shoulder 79 formed in the extension 80 of the casing, andthe outer end of the piston stem is provided with asuitable shoulder,shown as a transverse'pin 81, adapted to contact with collar 76 when thepiston stem moves inwardly.

The outer face of piston 71 is open to the atmosphere through port 83,and the chamber 72 on the inner face thereof communicates by passage 84with port: 85 in-the valve seat 67, and also communicates throughpassage 86 with the passage 26 leading to the service brake cylinder.

The valve seat 67 is provided adjacent to the port 85 with a port 87leading to an ex- .haust passage 88, and the slide valve 66 is providedon its lower face with a cavity 89 arranged in release position, asshown in Fig. 15, to connect ports 85 and 87 and therefore exhaustchamber 72 to the atmosphere. The valve seat 67 is also provided with alarge port 90 through which the stem .65 projects, and near its oppositeend with a small port 91 communicating through passage 92 with acored-out passage 93 around the bushing 14; and thence leading to thetrain pipe passage 11. A check valve 94, spring-seated away from thetrain pipe passage 11, controls this communication, so that air can flowinto the train pipe passage 11 past this check valve, but not in thereverse direction. valve 66 operates is connected by passage 97 with thesupplementary reservoir connection 34. Consequently, when the valve 66is in release position pressure flows from the supplementary reservoirconnection 3 1 through passage 97 into chamber 96 and thencethrough-port 91 and passages '92 and 93 past the check valve 941 to thetrain pipe connection 11. v

The chamber ea is connected through passage 100 and pipe 101 to thepressure chamher 102. The chamber 61 on the opposite face of thesupplementary piston 62 is open to the auxiliary reservoir through port:39 and passage 10, except in high pressure application and highpressure lap positions of the main valve. r

The high pressure brake cylinder passage 30 communicates with a passage105 leading to the cap 3 through a valve seat 106 surrounding thegraduating stem 107. In this connection is a check valve 108spring-seated away from the high pressure brake cylinder, so that fluidpressure can pass said valve toward the high pressure brake cylinder,but not in the reverse direction. The graduating stem 107 is normallyprojected into main piston chamber 4 by the graduating spring 110.Slidably surrounding said stem is a valve 111 seating on valve seat 106and normally held against said seat by compression spring 112. Ashoulder 113 on the graduating stem also assists in holding the valve111 on its seat. The graduating stem, however, has a pin and slotconnection 114 with said valve, so that the graduating stem can bepushed backwardly somewhat with out 'unseating valve 111. These partsare so arranged that under ordinary service and high pressure applcation reductions the' graduating stem .107 is not pushed out-.

Wardly so far .as'to unseat valve'lll, but

The chamber 96 in which slide,

upon emergency reductions of train pipe '6 pressure the graduating stem.is pushed backwardly so far that it unseats-valve 111 and therebypermits train pipe pressure to flow from the chamber 12 in the cap 3through passage 105 past the check valve 108 and thence to the highpressure brake cylinder.

The auxiliary reservoir 8 is of small capacity. While a certain amountof the air from this reservoir at times passes to the service brakecylinder, this is so limited that it is not the main braking medium. Theprincipal purpose of the auxiliary reservoir isto serve as a source ofpressure for effect-- ing certain'movements of the main and supplementalvalves. The valve mechanism de scribed has seven different functionalpositions as follows 1.

1. Full and quick release and running position. (Shown in Figs. 1, 2, 6and 15.) In-this position the main piston 5 is at its extreme forward orinward stroke and uncovers the feed groove 10 to permit train pipepressure to flow to the auxiliary reservoir and charge the same. Themain slide valve '16 is in such position that the enlarged lower end ofits port 47 laps over the inner end of the groove 41 and one end of theL-shaped port 33, so that air flows from the chamber 7 t0 thesupplementary reservoir, charging the same to the same pressure as theauxiliary reservoir. In this position cavity 58 in the graduating valve17 connects ports 48 and 19 of the main valve, 1.6, and which ports inturn register with exhaust port18 and service brake cylinder port 24respectively, while the L-shaped cavity 15 in the main slide valveconnects exhaust port 19 with high pressure brake cylinder port 29.Consequently, both brake cylinders are being exhausted to theatmosphere. The cut-away portion 52 of the main slide valve hasuncovered port 39 so that auxiliary reservoir pressure also flows to thechamber 61 of the supplementary valve mechanism, on the outer face ofthe supplementary piston 62; and said main slide valve has alsouncovered port 37, whence auxiliary reservoir air also flows to thepressure chamber 64 in the supplementary valve mecha nism. As aconsequence the pressures in the auxiliary reservoir, supplementaryreservoir, pressure chamber64 and chamber 61 on the outer face ofsupplemental piston 62, all equalize. Upon the release of the brakes,that is, by increase of brake pipe pressure, the pressures in chambers61 and 64. immediately equalize with auxiliary reservoir pressure.Consequently, the brake cylinder pressure in chamber 72 drives thesupplementary valve mechanismto the extreme left to the position shownin Figs. 2 and 15, which results in opening the exhaust port 87 to serveas an'auxiliary exhaust for the service brake cylinder. This alsoresults in carrying the collar 75 away from shoulder 78 and compressingspring 77. As soon as the brake cylinder pressure is substantiallyexhausted it relieves pressure in chamber 72 to such an extent that thespring 77 moves the supplementary valve mechanism to the right, untilthe collar 75 contacts with shoulder 78, leaving the supplementary valvein lap position, shown in Fig. 16. This position is maintained duringrunning. In this position the ports 85, 87 and 91 in the sup plementaryvalve seat are all closed and the remaining brake cylinder pressure isexhausted by way of ports 25, 24, 49, cavity 58 and ports 48, 18 and21in the main part of the valve.

Quick service or serial renting position. (Shown in Fig. 7.)Thisposition is assumed upon the first movement of the main piston upon aslight reduction of train pipe pressure and results in moving graduatingvalve 17 from the position shown in Fig. 6 to that shown in Fig. 7, butwithout moving the main slide valve 16, due to the lost motionconnection between the latter valve and the main piston stem. Thismovement results in breaking the connection between the service brakecylinder port 24 and the exhaust port 18, and establishes communicationthrough the cavity 59 in the graduating valve and ports 51 and 49 of themain slide valve between the train pipe port 22 and service brakecylinder port 24, thereby venting the train pipe momentarily to theservice brake cylinder, which is at atmospheric pressure, and producinga drop in pressure in the train pipe at the car and securing a quickerserial action of the brakes throughout the train than would be possibleif all the air had to flow forwardly and at the engineers brake valve.The air passing to the service brake cylinder produces a. light settingof the brakes. The valve remains in this position for a brief time, dueto the fact that the first movement of the piston 5 moves only the slidevalve 17 but as soon as the lostv motion between the piston stem 6 andthe slide valve 16 is taken up, the added frictional resistanceencountered momentarily checks the movement of the piston 5, therebyproviding an appreciable time of venting the train pipe. The reductionof train pipe pressure caused thereby produces a sufiicient unbalancingof pressures on the opposite sides of the main piston to over-- come thefriction of both slide valves, and the valve mechanism almostimmediately moves to the next position, now to be described.

3. Full service position. (Shown in Figs. 8 and 17.)In this position themain slide valve has moved so as to break connection between the highpressure brake cylinder port 29 and exhaust port 19 and between thetrain pipe port 22 and service brake cylinder port 24. It has alsocovered the pressure chamber port 37, and broken the connection betweenthe supplementary reservoir charging groove 41 and supplementaryreservoir port 33, thereby trapping the air in both the supplementaryreservoir and the pressure chamber. The port 39 leading to the auxiliaryreservoir side of supplementary piston 62 is, however, still open, sothat variations in auxiliary reservoir pressure are communicated to theouter face of supplementary piston 62. The port 50 in the main slidevalve in this position is uncovered by the graduating valve and alsocommunicates with the service brake cylinder port 24. Consequently,auxiliary reservoir pressure flows to the brake cylinder and produces alight setting of thebrakes. On account, however, of the small capacityof the auxiliary reservoir this results in practically a negligiblepressure in the service brake cylinder. It results, however, in a verymaterial reduction in auxiliary reser- "oir pressure, thereby producingan equivalent reduction on the outer face of supplementary piston 62,while the trapped pressure in the pressure chamber 64 remains con stant;as a consequence of which the supplementary piston 62 moves outwardly,that is, tothe right in Fig. 2, carrying with it the slide valve 66,which results in uncovering the port 85, as shown in Fig. 17, whencesupplementary reservoir pressure flows from chamber 96 through passage84, chamber 72, passage 86 to service brake cylinder connection 26 andthence to the service brake cylinder, thereby applying the brakes with apressure proportionate to the reduction in train pipe pressure. Thebrake cylinder pressure, it will be observed, also acts in chamber 72 onthe face of the small piston 71, and as soon as this pressure plus theauxiliary reservoir pressure on the outer face of piston 61 and thetension of spring 77 exceeds the trapped pressure in the pressurechamber 64 the supplementary piston moves backwardly or to lap position,shown in Fig. 16, but without connecting port 85 with exhaust port 87.It will be noticed that the collar 76 abuts against shoulder 79 beforethe piston stem 63 is moved entirely to its left-hand position, asindicated in Fig. 2. Consequently as soon as the supplementary piston isrelieved of the tension of spring 77 it comes to rest, without movingentirely to the left, which results in lapping the connection betweenthe supplementary reservoir and the brake cylinder, but without openingthe latter to exhaust. Should brake cylinder pressure leak off, itresults in a corresponding reduction of pressure in chamber 72 and theconstant pressure in chamber 64 will again move the supplementary valvemechanism to the right and again plementaryreservoir and service brakeicy-1.

inder, until the latter is again built 'up so that it will push thesupplementary valve mechanism to the left to lap position. Asaconsequence this supplementary" valve mechanism serves tomaintain-brake cylinder pressure constant, entirely irrespective ofbrake cylinder leakages or variations in piston travel in the brakecylinder, giving at all times a uniform pressure in the brake cylinderproportionate to the reduction of train pipe pressure.

4. Lap position. (Shown in Fig. 9.)

The reduction of auxiliary reservoir pressure by venting to the servicebrake cylinder, as described in the last previous position, results inthe main piston 5 moving inwardly, carrying with it the graduating valve17, but without moving the main slide valve 16. As a consequence thegraduating valve laps port 50 and. service brake cylinder port 24,thereby preventing further reduction on the auxiliary reservoir side ofthe main piston and on the outer face. of supplementary piston 62, andwhich condition will be maintained until the engineer further reducestrain pipe pressure, which will result in the repetition of themovements described in connection with the service application position,until full service pressure is reached. WVhile the main valve mechanismis in lap position the supplementary valve mechanism will continue tomaintain brake cylinder pressure against leak-age as hereinbeforedescribed. o

5. High pressure application position. (Shown in Fig, 10.)This positionis assumed after a full service application of the brakes (that is,equalization of auxiliary.

i'eservoiiyand service brake cylinder pressure), and 1n cases where theengineer desires a higher braking pressure; In mov ing to full serviceposition the end 0f the main piston abuts against the graduating stem107', and then stops, 'due, to thelresist ance of. graduating spring110. But when the higher braking pressure is'desired the engineerreduces train pipe pressure to such an extent that the piston 5 willmove backwardly and compress spring 110 until .the lost motion in theconnection between the graduating stem and valve 111 is taken up, en edded r is ance o spri g 112 is n ountered and his ca s s the al e 6 1 os ep he position llciwli v E n t s pos t n por 39 is lapped by he mainslide valve so that the pressure en the,

out f ce of upp e tary p ton 6-2 i ls trappe Th po t 47 of e ma n} lidvalve registers with the supplementary eser ir p rt 33, leth P the mainslide valve registers with the high Pressure brake cyl n er p rt 2 anthe avity 57 o he grad ating valve pnnects ports 46 andi lr', therebyestablishing communication from the supplementary-reserr.vo-ir'directlytto the high pressure brake cyl.-' inder. :This increasesthe braking power by the added power .of. the second cylinder. Toprevent overcharging the high pressure brake cylinder when the valve isin this position the port 50 of the main slide valve is uncovered by thegraduating .Valve and is also partly in register with the exhaust port18, as a'result of which auxiliary reservoir pressure is slowlyexhausted to the atmosphere, and as soon as the pressure on theauxiliary reservoir side; of the main piston drops slightly below trainpipe pressure the main piston is moved back by the gradu: ating spring,thereby moving the graduating valve back to the position next to bedescribed, in which it laps the port 50, pre-. venting further ventingon the auxiliary reservoir side ofthe main piston, and also breakingconnection between the supplementaryreservoir and high pressure brakecylinder. The connection from the supplementary reservoir to the highpressure cylinder may be established as frequently as necessary bysuccessive reductions of train pipe pressure, until the supplementaryreservoir has equalized with the high pressure brake cylinder.

6. High pressure Zap position, Shown in.=Fig.'11.)This position isassumed by the lapping back of the graduating valve,

due to the. leaking pfi of auxiliary reservoir pressure through port 50and exhaust port 18, asjust described. The efiect is to break theconnection between the supplementary vreservoir andthe emergency brake,cylinder.

'high pressure application is established without destroying or reducingthe sensitiveness of-the vvalve as torelease or disturbing the brakingeffect of the 1 other triple valves in the train. The brake rigging canbe so adjusted that the full service applicaation of the brakes providessuflicient power to' hold the car-when empty, and (by using. the highpressure application above de r e 1 P w xc b a ed des to hold the car onsteep gradeswhen loaded, so" that the use of hand-brakes in coming downsteep grades can be entirely, dispensed with, During the, high pressureapplication the supplementary valve mechanism serves to V maintainservice brake cylinderv pressure against leakage,-. in exactly the same,way. as

itdoes during Qlidiiiary ser ice p li iqnsi 7. Emergency position.(Shown in Fig. l2.)-This position is assumed upon a sudden reduction intrain pipe pressure, which moves the main piston 5 to compress both thesprings 110 and 112 and move fully outwardly, thereby dragging out bothslide valves. The full movement of the piston 5 outwardly has taken upthe lost motion between graduating stem 107 and valve 111,

. thereby unseating the latter valve and permitting train pipe pressureto rush through passage 105, past check valve 108 and through passage 30to the high pressure brake cylinder. This not only supplies the highpressure brake cylinder with air but also produces a quick serial actionof the brakes through the train. As soon as the pressure in the highpressure brake cylinder sure rushes to the service brake cylinder and.

this also depletes the pressure on the outer face ofpiston 62correspondingly, so that piston 62 and slide valve 66 move fully overtoward'the right, establishing communication from the supplementaryreservoir to the service brake cylinder by way of passage 97, chamber96, port 85, chamber 72 and passage 86. Also, in this position port 47in main, slide valve connects supplementary reservoir port 33 with highpressure cylinder port 29. Consequently, this position results incomplete equalization between supplementa ry reservoir, auxiliaryreservoir and both brake cylinders. The pressure chamber, however, stillcontinues to be trapped so that it holds the supplementary piston fullyover to the right.

The emergency position of the valve can be secured either directly fromfull release position or from any of the other positions of the valve bysuddenly reducing the train pipe pressurebelow the point of equalizationof the auxiliary reservoir pressure with brake cylinder pressure.

The valve mechanism described performs all of the usual functions offreight triple valves, and in'addition provides for a quick serviceapplication of the brakes, a quick release of the brakes, and for thehigh pressure application after full service application as abovedescribed. It is further soarranged as to secure uniform pressure inboth service and high pressure applications irrespective of pistontravel, and to maintain such pressure against leakage. power can besecured in high pressure application position to hold loaded cars whengoing down steep grades, so as to dispense with the use of hand-brakes.

lVhat I claim is:

1. In a fluid pressure brake, the combination of a train pipe, a pair ofbrake cylinders, two reservoirs on a car, and means operative byvariation in train pipe pressure and arranged on service reduction oftrain pipe pressure to connect first one and then the other of saidreservoirs to one of said brake cylinders, and upon reduction of trainpipe pressure after full service application to connect one of saidreservoirs to the other brake cylinder.

2. In a fluid pressure brake, the combination of a train pipe, a pair ofbrake cylinders, two reservoirs on a car, and means operative byvariations in train pipe pressure and arranged on service reduction oftrain pipe pressure to connect first one and then the other of saidreservoirs to one of said brake cylinders, upon reduction of train pipepressure after full service application to connect one of saidreservoirs to the other brake cylinder, and upon emergency reduction oftrain pipe pressure to connect both of said reservoirs to both of saidbrake cylinders 3. Ina fluid pressure brake. the comb nation of a trainpipe, a pair of brake cvlinders, two reservoirson a car, and meansoperative by variations in train pipe pressure and arranged on servicereduction in train pipe pressure to connect first one and then the otherof said reservoirs to one of said brake. cylinders. upon reduction oftrain pipe pressure after full service application to connect one ofsaid reservoirs to the other brake cvlinder. and upon emergencvreductionof train pipe pressure to connect both of said reservoirs and a sourceof pressure to both brake cylinders.

4:. In a fluid pressure brake. the combination of a train pipe, a'pairof brake cylinders, two reservoirs on a car, and means operative byvariations in train pipe pressure and arranged on service reduction oftrain pipe pressure to connect first one and then the other of saidreservoirs to one of said brake cylinders, and upon reduction of trainpipe pressure after full service application to connect one of saidreservoirs to the other brake cylinder, said means including asupplementary valve device controlled by variations in reservoirpressure and arranged to maintain brake cylinder pressure againstleakage.

In a fluid pressure brake, the combination of a train pipe, a pair ofbrake cylinders, two reservoirs on a car, and means operative byvariations in train pipe pressure and arranged upon service reduction intrain pipe pressure. to connect first one and then the other of saidreservoirs with one of said: brakecylinders; uponzreducti-on of.

train pipe pressure after: full service application to; connect. oneoifsaid" reservoirs to the other brakecyhnder; said means including asupplementary valve device controlled by'variations in the. pressureotthe other of said reservoirs and arranged to maintain brake cylinderpressure against leakage.

6. In a fluid pressure brake, the combination of a train pipe, a pair ofbrake cylinders, two reservoirs on a car, and means operative byvariations in train pipe pressure and arranged on service reduction intrain pipe pressure to'connect first one and then the other of saidreservoirs to one of said brake cylinders; upon reduction of train pipepressure. a ter-full service ap lication to connect one of saidreservoirsto the other brake-cvlinder.. and upon emergency reduc tion oftrain pipe pressure to connect both of'said reservoirs 'toboth of saidbrake cvlinders said means'including a supple-1 mentary valve devicecontrolledby' variatlons-in reservoirpressure and arranged to leakage; iI

7. In fluid-pressure brake, the c n'n'b1m 1 maintain brakej'cylinderE'pressuret, against tion of a 'train pipe, apair of brakecylin:

ders, two reservoirs on a car, andlimeans operative by variationsintrain pipe" pressure and arranged on service reduction of train pipepressure to connect first one a'nd then the other of said reservoirs too ne-of; said brake cylinders, upon reduction of train pipe pressureafter full service application to connect one of said reservoirs to theother brake cylinder; and upon emergency reduction in train pipepressure to connect both of said reservoirs and a source of pressure toboth brake cylinders, said means including asupplementary valve devicecontrolled by variations in the pressure in one of said reservoirs andarranged to maintain brake cylinder pressure against leakage.

8. In a fluid pressure brake, the combination' of a train pipe, twobrake cylinders,- a reservoir a pressure chamber, Valve 1nechanismactuated by variations in train pipe pressure and arranged upon servicereduction in train pipe pressure to open communication between saidreservoir and one of said brake cylinders and to trap pressure in thepressure chamber, and upon emergency reduction in train pipe pressure toestablish communication between a source of pressure and the other brakecylinder, and means subject to the pressures in said pressure chamberand reservoir and arranged to maintain brake cylinder pressure againstleakage.

9. In a fluid pressure brake, the combination of a train pipe, two brakecylinders, a reservoir, a pressure chamber, valve mechanism actuated byvariations in train pipe pressure and arranged upon service reducgeneyreduction" in train 'pipe prcssure'to establish communication between asource of pressure and the other brake cylinder, and means subject tothe pressures in the same pressure chamber and reservoir and arrangedupon reductions in reservoir pressure to open communication between: anadditional source of pressure and a brake cylinderfi I 1 10. In a fluidpressure brake, the combination of a train pipe, two brake cylinders, anauxiliary reservoir, a supplementary reservoir, a constant pressurechamber in communication with the auxiliary reservoir in runningposition, means actuatedby variations'in train pipe pressureand arrangeduponreduction'in train pipe pressure to con'- nect'said auxiliary.reservoir to one of-s'aid brake i-cylinders and to j close said pressurechain-her and trap pressure thereii'i, and supconnect the supplementaryreservoir to said.

brake cylinder; A g

-11. In as'iiuid pressure brake, the co'i'nbliia tiou: of ai traiiil"pipe, two brake cylinders,

two" reservoirs on a car, and means operative by variations intrain pipepressure and ar-' ranged upon 'service' reduction in train pipe pressureto connect first one and then the other of. said reservoirsto one ofsaid brake cylinders and upon reduction of train pipe pressure afterfull service application to connect one of said reservoirs to the otherbrake cylinder, said means including a supplementary valve devicesubject to brake cylinder pressure and to the pressure in one of saidreservoirs and arranged to maintain brake cylinder pressure againstleakage.

12. In a fluid pressure brake, the com bination of atrainj pipe, a pairof brake cylinders, two reservoirs on a car, and means operative byvariations'in train pipe pressure'and arranged upon service reduction intrain pipe pressure to connect first one and then the other of saidreservoirs with one of said brake cylinders, and uponreduction of trainpipe pressure after :t'ullscrvice apmunication between the other of saidreseiy voirs and the first named brake cylinder.

13. In a fluid'pressure brake, the combinaticn of a train pipe, twobrake cylinders,

two reservoirs on a. car, means operated by variations in train pipepressure and ar= ranged on service reduction in train pipe pressure toconnect first one and then the other of said reservoirs to one of saidbrake cylinders upon further reduction of train pipe pressure to connectone of said reservoirs to the other brake cylinder, and upon emergencyreduction in train pipe pressure to connect both of said reservoirs toboth of said cylinders, said means including a supplementary valvedevice subject to brake cylinder pressure and to the pressure in one ofsaid reservoirs and main slide valve mechanism.

14:. In a fluid pressure brake, the combination of a train pipe, twobrake cylinders, two reservoirs on a car, means operative by variationsin train pipe pressure and arranged on reduction in train pipe pressureto connect one of said reservoirs with the brake cylinders,a pressurechamber in communication with said reservoir in running position, andmeans subject to the pressures in said chamber and reservoir andarranged upon variations in the pressures therein to connect the otherreservoir to one of the brake cylinders.

15. In a fluid pressure brake, the combination of a train pipe, twobrake cylinders, auxiliary reservoir, and pressure chamber, valvemechanism actuated by variations in train pipe pressure and arrangedupon service re .duction in train pipe pressure to open communicationbetween the auxiliary reservoir and one brake cylmder and to trappressure in the pressure chamber, and upon reduction in train pipepressure after full service application to open communication between anadditional source of pressure and the other brake cylinder, and meanssubject to brake cylinder pressure-and to the pressure in said pressurechamber and auxiliary reservoir and arranged to maintain brake cylinderpressure against leakage.

16. In a fluid pressure brake, the combination of a train pipe, twobrake cylinders, auxiliary reservoir, supplementary reservoir, andpressure chamber, valve mechanism actuated by variations in train pipepressure and arranged upon service reduction in train pipe pressune toopen communi cation between the auxiliary reservoir and one of saidbrake cylinders and to trap pressure in said chamber, and upon reductionin train pipe pressure after full service application to opencommunication between the supplementary reservoir and other brakecylinder, and means subject to brake cylinder pressure and to thepressures in the pressure chamber and auxiliary reservoir and arrangedupon variations in said pressures to control communication between thesupplementary reservoir and the first named brake cylinder.

In testimony whereof, I have hereunto set my hand.

' JACOB RUSH SNYDER. Witnesses: ELBERT L. HYDE, GLENN H. LERESOI-IE.

Copies of this patent may be obtained for five cents each. by addressingthe Commissioner of Patents.

Washington, D. C.

